package com.bms.tools;

import java.security.MessageDigest;

import javax.crypto.KeyGenerator;
import javax.crypto.Mac;
import javax.crypto.SecretKey;
import javax.crypto.spec.SecretKeySpec;

import sun.misc.BASE64Decoder;
import sun.misc.BASE64Encoder;


public class EncryptionTool {
	
	public static final String KEY_SHA = "SHA";  
	public static final String KEY_MD5 = "MD5";  

	/** 
	 * MAC算法可选以下多种算法 
	 *  
	 * <pre> 
	 * HmacMD5  
	 * HmacSHA1  
	 * HmacSHA256  
	 * HmacSHA384  
	 * HmacSHA512 
	 * </pre> 
	 */  
	public static final String KEY_MAC = "HmacMD5";

	/**
	 * SHA加密
	 * @param data
	 * @return
	 * @throws Exception
	 */
	public static byte[] encryptSHA(byte[] data) throws Exception {  
	        MessageDigest sha = MessageDigest.getInstance(KEY_SHA);  
	        sha.update(data);  
	        return sha.digest();  
    } 
	
 	 /**
     * BASE64解密 
     *  
     * @param key 
     * @return 
     * @throws Exception 
     */  
    public static byte[] decryptBASE64(String key) throws Exception {  
        return (new BASE64Decoder()).decodeBuffer(key);  
    }  
  
    /** 
     * BASE64加密 
     *  
     * @param key 
     * @return 
     * @throws Exception 
     */  
    public static String encryptBASE64(byte[] key) throws Exception {  
        return (new BASE64Encoder()).encodeBuffer(key);  
    }  
    
    /** 
     * MD5加密 
     *  
     * @param data 
     * @return 
     * @throws Exception 
     */  
    public static byte[] encryptMD5(byte[] data) throws Exception {  
        MessageDigest md5 = MessageDigest.getInstance(KEY_MD5);  
        md5.update(data);  
        return md5.digest();  
  
    }  
    
    /** 
    * 初始化HMAC密钥 
    *  
    * @return 
    * @throws Exception 
    */  
   public static String initMacKey() throws Exception {  
       KeyGenerator keyGenerator = KeyGenerator.getInstance(KEY_MAC);  
 
       SecretKey secretKey = keyGenerator.generateKey();  
       return encryptBASE64(secretKey.getEncoded());  
   }  
  
    /** 
     * HMAC加密 
     *  
     * @param data 
     * @param key 
     * @return 
     * @throws Exception 
     */  
    public static byte[] encryptHMAC(byte[] data) throws Exception {  
  
        SecretKey secretKey = new SecretKeySpec(data, KEY_MAC);  
        Mac mac = Mac.getInstance(secretKey.getAlgorithm());  
        mac.init(secretKey);  
  
        return mac.doFinal(data);  
  
    }  

    
    /**
     * BMS用户注册，密码加密方式
     * @param data
     * @return
     * @throws Exception
     */
    public static String encryptBMSPassWord(byte[] data) throws Exception { 
    	
    	//先用MD5加密
        byte[] md5Byte = encryptMD5(data);
        
        //再用SHA加密
        byte[] shaByte = encryptSHA(md5Byte);
        
        //BASE64加密
        String res     = encryptBASE64(shaByte);
        
        return res;  
    }
    

}
